That number will be 100% dependent on the style of life you are living now (ie how much you spend vs how much you make) and WHERE you live (cost basis for various countries differ greatly)
VS 
The changes you are able to make to build the life you want, once you decide what you want, and what you are willing to sacrifice to get it… 
Happy to continue the convo via DM 
There is no simply answer to that question, but I am happy to share my thoughts and opinions on the subject